JP4063518B2

JP4063518B2 - Pipe-shaped member and method for forming the same

Info

Publication number: JP4063518B2
Application number: JP2001313701A
Authority: JP
Inventors: 博幸黒川; 浩貴首藤; 達司清水; 英輔岡本
Original assignee: Mitsubishi Motors Corp
Current assignee: Mitsubishi Motors Corp
Priority date: 2001-10-11
Filing date: 2001-10-11
Publication date: 2008-03-19
Anticipated expiration: 2021-10-11
Also published as: JP2003117622A

Description

【０００１】
【発明の属する技術分野】
本発明は、単一パイプ素材によって所定形状に成形されるパイプ状部材及びその成形方法、特に、長手方向の各位置での断面外径が変化するパイプ状部材及びその成形方法に関する。
【０００２】
【従来の技術】
パイプ状部材は各種産業機器の構成部品として使用される。このようなパイプ状部材の製作にあたっては、適宜外径のパイプ素材が採用され、これが所定の形状に変形加工されパイプ状部材として完成した上で構成部品として各産業機器に組込まれている。このようなパイプ素材を製品として加工するにあたっては、多数の変形加工方法が採用されている。例えば、長手方向の各位置での断面外径が変化するパイプ状部材を金属で製作する場合、ハイドロフォーム加工法により拡径成形することが知られている。
このハイドロフォーム加工法によれば、図１３（ａ）に示すように、パイプ素材はその長手方向両端部において拡管率が変化するパイプ状部材１００として成形可能であるが、従来のハイドロフォーム加工法によって得られる断面形状変化率である拡管率の最大値は５〜１０％が限界である。
【０００３】
そこで、それ以上に長手方向両端部において拡管率を変化させたパイプ状部材を製作するには、図１３（ｂ）に示すように、大小異なる断面形状の２つのパイプ素材１１０、１２０を板金加工等で別途製作したブラケット１３０を用いて接続してパイプ状部材１４０として製作することとなり、あるいは金属以外の全く異なる素材のパイプを用い適宜の成形加工をすることと成る。
【０００４】
【発明が解決しようとする課題】
しかし、図１３（ｂ）に示すように、複数のパイプ材１１０、１２０をブラケット１３０で接続するという製作法を採った場合、部品数増加、溶接作業工数増加等を招き、しかも、安定した強度が得られない場合がある。これに対して、ハイドロフォーム加工法によるパイプ状部材は、部品数減、溶接作業工数減、安定した強度が得られるが、上述のように十分な拡管率が得られず、形状が規制されるという問題がある。
このようにハイドロフォーム加工法で得られたパイプ状部材が長手方向の各位置での断面面積が十分に変化するものとして成形できれば有効利用できることとなり、改善が望まれている。
【０００５】
例えば、リアドアがスライドドアである車体構造では、ルーフサイドレールにスライドドアレールの収容空間が確保されていることから閉断面の断面積が大きく変化している。このような車体構造において、フロントピラーから連続するルーフサイドレールの補強として、フロントピラー及びルーフサイドの閉断面内部に連続して単一のパイプ状部材を嵌挿するとした場合、パイプ状部材は長手方向の各位置でサイドルーフレールやピラーの各断面に応じた断面形状を持ちながら、断面剛性及び衝突強度を減少させないことが望まれている。
本発明は、以上のような課題に基づき、長手方向の各位置での断面の面積が十分に変化するパイプ状部材及びその成形方法を提供することを目的とする。
【０００６】
【課題を解決するための手段】
請求項１の発明によるパイプ状部材は、プレス加工により断面内方に突出する内突部が形成された縮径部と同縮径部に連続して形成される拡径部とを有し、前記内突部の外周側基部が溶接され、前記縮径部及び拡径部がハイドロフォーム加工されたことを特徴とする。
このように、内突部が形成された縮径部とこれに連続する拡径部とを単一パイプ材によりハイドロフォーム加工して形成するので、部品点数削減、組み付け工数低減を図れ、特に、前記内突部の外周側基部が溶接されるので、変形時に外周側基部が分離変形せず、同部の変形時の剛性を強化できる。
【０００８】
請求項２の発明によるパイプ状部材の成形方法は、パイプ素材にプレス加工により断面内方に突出する内突部を形成する第１の工程と、前記パイプ素材をハイドロフォーム加工により拡径してパイプ状部材を成形する第２の工程と、前記内突部の外周側基部を溶接する第３の工程とを有し、前記第１の工程は、前記パイプ素材をく字状閉断面に形成する第１のプレス加工工程と、前記第１のプレス加工工程終了後、前記く字状閉断面の両屈曲端を互いに接近する方向に圧縮して当接させる第２のプレス加工工程とを有することを特徴とする。
このように第１の工程で内突部を形成し、第２の工程で内突部の形成された部位である縮径部とこれに連続する拡径部とを単一パイプ素材によりハイドロフォーム加工して形成し、第３の工程において前記内突部の外周側基部が溶接されるので、断面の外径変化率（拡管率）の大きいパイプ状部材を単一パイプ素材により作業性よく成形でき、内突部による剛性の向上及びハイドロフォーム加工による加工硬化での剛性の向上を図ることができ、変形時に外周側基部が分離変形せず、変形時の剛性を強化したパイプ状部材を容易に作成できる。特に、パイプ素材を２度のプレス加工でく字状閉断面の両屈曲端を互いに当接変形させて縮径部に予備成形し、その上で第２の工程でハイドロフォーム加工により縮径部を含む全体を拡径成形することができ、作業性よく縮径部を含むパイプ状部材を成形できる。
【００１１】
【発明の実施の形態】
以下、本発明の一実施形態としてのパイプ状部材及びパイプ状部材の成形方法を説明する。
図１（ａ），（ｂ）に示すパイプ状部材としてのパイプ状補強部材１は、図示しない車体側部の前後開口６、７の上部のフロントピラー２及びその後端に連続して形成されたルーフサイドレール３とにわたって嵌着され、これら部位の剛性強化を図っている。パイプ状補強部材１は比較的大径の湾曲部ａ１を有した拡径部である前側部ａと、後開口７の上端縁対向部と対向する部位が小径化された縮径部ｂとを連続して形成される。
【００１２】
ここでパイプ状補強部材１の拡径部である前側部ａは、図１（ａ）に示すように、フロントピラー２及びルーフサイドレール３の前端側に対向し、同部のフロントピラー２及びルーフサイドレール３のインナ部材側に長手方向の複数箇所において溶接される。なお、図７（ａ）にはルーフサイドレール３の前端側のルーフサイドレールインナ３２への溶接部ｗを示し、図７（ｂ）にはルーフサイドレール３の後方側である縮径部ｂにおけるルーフサイドレールエクステンションアッパー３４への溶接部ｗを示した。
【００１３】
このように使用されるパイプ状補強部材１は単一の鋼管がパイプ素材ｍとして採用され、図２、３、４に示すようなプレス機１０及びハイドロフォーム加工機１１により、湾曲部ａ１を有した前側部ａ及び縮径部ｂの加工が行われる。
ここで用いるプレス機１０は、図２、３に示すように、基台１２とその上方に延出する縦基枠１３を有し、基台１２上にパイプ載置面１４を形成すると共にその両側に固定型１５、第１、第２可動型１６、１７を配備し、縦基枠１３に上型１８を取付ける。
【００１４】
基台１２上の固定型１５内にはストッパ２０及び同ストッパ２０を退却位置ｐ１とストッパ位置ｐ２とに切換える第１加圧機１９が装着される。第１可動型１６は縮径部ｂを形成するもので、退却位置ｐ３、抑え位置ｐ４、加圧位置ｐ５及び加圧前位置ｐ５’とに切換える第２加圧機２１が装着される。第２可動型１７はパイプ素材ｍに湾曲部a１を形成するもので、退却位置ｐ６と加圧位置ｐ７とに切換える第３加圧機２２が装着される。上型１８は縮径部ｂに凹部ｑ（図５（ｂ）参照）を形成するもので、退却位置ｐ８、プレス位置ｐ９とに切換える第４加圧機２３が装着される。なお、上型１８は複数の横基枠２４に支持され、これら横基枠２４は４角の縦基枠１３に支持される。図３中符号２５は上型１８の両端より上方に延出する回り止め部材で、横基枠２４側に摺動可能に嵌挿される。
【００１５】
図４に示すようにハイドロフォーム加工機１１は、上下型１１１、１１２を有する型締め機（図示せず）とその両側に配備される高圧水供給アダプタ２６、２６を備える。上下型１１１、１１２は両者の上下接合面に後述の第１の工程終了後のパイプ素材ｍを密に嵌着する嵌合溝（図６（ａ）参照）１１３、１１４を凹設される。各高圧水供給アダプタ２６はパイプ素材ｍの両端部（図１、図４参照）に嵌着可能に形成されている。高圧水供給アダプタ２６はパイプ素材の両端部ｎに密に嵌合可能な構造を採り、ハイドロフォーム加工機１１の図示しない本体の超高圧水供給系とパイプ素材ｍを連通するもので、アダプタ支持台２７に支持される。アダプタ支持台２７は内部に図示しない加圧機構を装着しており、これにより高圧水供給アダプタ２６及びパイプ素材ｍを共にその軸心方向に押圧する加圧力ＰＷを加え、パイプ素材ｍの拡径加工を促進させる。
【００１６】
このようなプレス機１０及びハイドロフォーム加工機１１を用い、図１のパイプ状補強部材１を成形加工するパイプ状部材の成形方法を図２、３、４を参照し、図５（ａ）〜（ｃ）、図６（ａ）、（ｂ）に沿って説明する。
パイプ状部材１の成形に先立ち、所定外径で所定長さの鋼製のパイプ素材ｍがプレス機１０に供給される。この場合、パイプ素材ｍの外径はパイプ状補強部材１の前側部ａの外径より所定量小さな外径のものが採用される。この場合、パイプ素材ｍはこれが５〜１０％の拡管率で変形した際にパイプ状補強部材１の前側部ａの外径が得られるようなものが選択される。
【００１７】
プレス機１０は、ストッパ２０を退却位置ｐ１に、第１、第２可動型１６、１７を退却位置ｐ３、ｐ６に、上型１８を退却位置ｐ８にそれぞれ保持した上で、基台１２上のパイプ載置面１４にパイプ素材ｍが供給される。次いで、図２、図５（ａ）に示すように、第１、第２可動型１６、１７を退却位置ｐ３、ｐ６より抑え位置ｐ４、加圧位置ｐ７に切換え、パイプ素材ｍに湾曲部ａ１を形成する。次いで、図５（ｂ）に示すように、第１可動型１６のみが抑え位置ｐ４より加圧前位置ｐ５’に移動して固定型１５及び可動型１６、１７間の上方開口ｈを拡大させる。その上で、上型１８は退却位置ｐ８より降下してプレス位置ｐ９に達し、パイプ素材ｍに凹部ｑを形成する第１のプレス加工工程が行われる。これによりパイプ素材ｍの上型１８との対向部にはく字状閉断面ｕが形成されることとなる。
【００１８】
次いで、図５（ｃ）に示すように、上型１８は再度上昇して退却位置ｐ８に戻る。その上で、ストッパ２０が退却位置ｐ１よりストッパ位置ｐ２に突出し、パイプ素材ｍの凹部ｑが形成された部位の上方へのずれを抑える。この状態で、第１可動型１６のみが加圧前位置ｐ５’より移動して加圧位置ｐ５に達し、固定型１５と第１可動型１６のプレス面が、く字状閉断面ｕを成している部位の両屈曲端を互いに接近する方向に圧縮し、互いに当接させる第２のプレス加工工程が成される。このように第１、第２の各プレス加工工程により第１の工程を完了し、この部位を縮径部ｂとして形成することができる。この場合、パイプ素材ｍの縮径部ｂには閉断面内方に突出する内側突状の内突部１０１が形成される。
【００１９】
次いで、第１の工程を完了したパイプ素材ｍはプレス機１０の型開きの後、取出され、図４及びハイドロフォーム加工機１１に示すように、下型１１２の嵌合溝１１４に嵌着され、その上で、型締め機（図示せず）で型閉めされ、上下の嵌合溝（図６（ａ）参照）１１３、１１４に密に嵌着される。
次いで上下型１１１、１１２に挟圧された状態でパイプ素材ｍの両端部ｎに高圧水供給アダプタ２６がそれぞれ取付けられると、ハイドロフォーム加工機１１の図示しない本体より高圧水がパイプ素材ｍの内部に供給され、パイプ素材ｍは拡径成形され、パイプ状補強部材１に成形され、第２の工程が完了する。この際、縮径部ｂの内側突状の内突部１０１は全周面が超高圧水の液圧を受けて内部隙間を潰され、図６（ａ）に示すような板状に近い内突部１０１として成形される。
【００２０】
このようにパイプ素材ｍを２度のプレス加工でく字状閉断面ｕの両屈曲端を互いに接近変形させて縮径部ｂに予備成形し、その上で第２の工程でハイドロフォーム加工により縮径部ｂを含む全体を拡径成形することができ、作業性よく縮径部ｂを含む補強部材１を成形できる。
次いで、ハイドロフォーム加工機１１は型開きされ、高圧水供給アダプタ２６が外され、パイプ状補強部材１が取り出される。
更にパイプ状補強部材１はその両端個所の高圧水供給アダプタ２６と連結されていた端部ｎの内、縮径部ｂ側の端部ｎを切断される。更に、図６（ｂ）に示すように、パイプ状補強部材１はその縮径部ｂの内突部１０１の外周側基部ｅがその位置を溶接部ｗとして処理され、第３の工程を完了して完成品となる。
【００２１】
このように第３の工程において内突部１０１の外周側基部ｅが溶接部ｗとなるので、変形時に外周側基部ｅが分離変形せず、変形時の剛性を強化できる。
完成品となったパイプ状補強部材１は図１（ａ）に示すように、車両Ｖのフロントピラー２及びルーフサイドレール３に補強部材として使用される。
このように成形されたパイプ状補強部材１は図１（ａ），（ｂ）及び図７に示すように、その縮径部ｂにおいて、内突部１０１を横向きで配置し、その外側端である外周側基部ｅが車両の側端側に位置している。図７に示すように外周側基部ｅの上下には丸く突出た片状部がそれぞれ形成され、パイプ状補強部材１はその全体が横向きハート型の断面形状を呈して縮径成形される。
【００２２】
このような形状のパイプ状補強部材１の縮径部ｂは内突部１０１を形成することで拡管率を十分大きくして成形される。即ち、パイプ状補強部材１をハイドロフォーム成型により長手方向の各位置での断面積を変化させて形成する場合、通常のハイドロフォーム成型であると、拡管率が５乃至１０％程度である。しかし、ここではあらかじめ比較的外形の大きなパイプ素材ｍを用意し、パイプ素材の一部を縮径加工し、その上で拡径加工する。ここで縮径加工では縮径部ｂにおいて内突部１０１がプレス加工で凹設されて縮径成形され、拡管率を十分に大きく確保できる。次いで、パイプ素材ｍ全体をプレス機１０で型締めし、通常の拡管率が５乃至１０％程度でのハイドロフォーム成型を行い、パイプ状補強部材１を成形した。このため、パイプ状補強部材１は、結果的に拡管率を十分に大きなものとして成形したと同様の加工が行われたこととなる。しかも、縮径部ｂは内突部１０１の外側端である外周側基部ｅを溶接されたため、屈曲変形時の外周側基部ｅの変形を抑えることより、屈曲強度を向上できる。
【００２３】
このようなパイプ状補強部材１を図示しない車体側部の前後開口６、７の上部のフロントピラー２及びその後端に連続するルーフサイドレール３とにわたって嵌着する使用例を以下に説明する。
図７（ａ）に示すように、ルーフサイドレール３は、車両の前開口６の開口上部において、ルーフサイドレールアウタ３１とルーフサイドレールインナ３２とが互いに重ねられて内外フランジが溶接された閉断面として形成される。この閉断面の部位にパイプ状補強部材１の前側部ａが嵌挿され、ルーフサイドレールインナ３２に当接され、複数の溶接部ｗで互いに溶接されている。なお、パイプ状補強部材１の前側部ａとルーフサイドレールインナ３２との溶接部位に対してその前側に連続するフロントピラー２の上部側部位でもほぼ同様の構成を採るが重複説明を略す。
【００２４】
図７（ｂ）に示すように、ルーフサイドレール３は、車両の後開口７の開口上部において、主部３ａと空域部３ｂとその下方の図示しない補助部とで形成されている。主部３ａはルーフサイドアウターパネル３３とルーフサイドレールエクステンションアッパー３４とを一体結合した閉断面構造を比較的小さく形成される。ここで閉断面空間にはパイプ状補強部材１の縮径部ｂが嵌挿され、同縮径部ｂとルーフサイドレールエクステンションアッパー３４との当接部が長手方向に沿って複数の溶接部Ｗで間欠的に溶接されている。
【００２５】
なお、空域部３ｂの最深部に延びるルーフインナパネル３５には図示しないスライドドア用のスライドドアレールが取付けられる。
このようなパイプ状補強部材１をフロントピラー２及びルーフサイドレール３に嵌挿した車両Ｖが走行時に正面衝突やオフセット衝突して、フロントピラー２よりルーフサイドレール３に向けて過荷重が加わると、ここでフロントピラー２やルーフサイドレール３の前端部はパイプ状補強部材１の比較的大径の前部により十分補強されていることで、屈曲を十分抑えられる。
【００２６】
特に、図１（ｂ）、図７（ｂ）に示すように、パイプ状補強部材１はその段差部Ｄより縮径部ｂに続く部位でハート型の断面形状を呈し、外側端に外周側基部ｅが位置した内突部１０１を横向きで配置している。このため、外周側基部ｅが縮径部ｂの剛性及び衝突強度を特に強化するので、縮径部ｂの剛性中心(断面方向での圧縮力と引張力が釣合って打ち消される位置)となる軸心ｙ２（軸心線Ｌ２参照）に対して、前側部ａの剛性中心となる軸心ｙ１（軸心線Ｌ１参照）のずれδが比較的小さく抑えられる。しかも、外周側基部ｅが溶接されることによっても外周側基部ｅの剛性を高めている。この点より、ルーフサイドレール３の段差部Ｄが屈曲し始めたとしても、パイプ状補強部材１の内突部１０１がその屈曲変位を十分抑制できる。
【００２７】
このように、単一の部品であるパイプ状補強部材１は長手方向の各位置での閉断面形状が大きく変化するフロントピラー２及びルーフサイドレール３に容易に嵌挿でき、一体結合されることで同部の剛性を十分に強化できる。特に、パイプ状補強部材１はフロントピラー２よりルーフサイドレール３にわたって連続して嵌挿できることで部品点数削減、溶接工数削減、コスト低減に寄与できる。更に、縮径部ｂがその内突部１０１により剛性の向上を図られ、しかも、ハイドロフォーム加工による加工硬化でパイプ状補強部材１全体の剛性の向上を図ることができる。
【００２８】
上述のところにおいて、パイプ状補強部材１はその縮径部ｂに内突部１０１を配置しており、同内突部１０１は外側端に外周側基部ｅが位置し、横向きで配置されていたが、これに代えて、図８、９に示すように、構成しても良い。なお、ここでのパイプ状補強部材１ａは内突部１０１ａを縦向きに配設する点が相違する以外は図１のパイプ状補強部材１と同様に形成され、同様に使用されることより、同一部材には同一符号を付し、重複説明を略す。
この場合のパイプ状補強部材１ａはその縮径部ｂａにおける内突部１０１ａの外周側基部ｅａを下側に配置し、内突部１０１ａを下側の外周側基部ｅａより上向きに延出し、縮径部ｂａの閉断面内に縦向きに配置している。
【００２９】
このように使用されるパイプ状補強部材１ａは、図１０（ａ），（ｂ）に示すようなプレス機１０ａ及び上述と同様のハイドロフォーム加工機１１が使用される。
ここで用いるプレス機１０ａは、基台４０とその上方に延出する縦基枠４１を有し、基台４０上の一部に補助基台４２を一体的に取付け、パイプ載置面４３を形成すると共にその両側に第１、第２可動型４４、４５を配備し、パイプ載置面４３の上方に縦基枠４１側に支持された上型４６を配備する。
基台４０上には第１、第２加圧機４７ａ、４７ｂが装着され、これにより第１、第２可動型４４、４５が開放位置ｑ１とプレス位置ｑ２とに切換えられる。第１、第２可動型４４、４５上には第３、第４加圧機４８、４９が装着され、これにより一対の挟持型５０、５１を退却位置ｑ３とプレス位置ｑ４（図１１（ｃ）参照）とに切換える。
【００３０】
上型４６は縦基枠４１側に回動不可に摺動自在に支持され、縦基枠４１側に支持された第５加圧機５０により退却位置ｑ５とプラス位置ｑ６に切換えられる。上型４６及びその支持部材４６１上には直状型５３が摺動可能に支持され、同直状型５３は第６加圧機５２により退却位置ｑ７とプレス位置ｑ８に切換えられる。
このようなプレス機１０ａ及びハイドロフォーム加工機１１を用い、図８のパイプ状補強部材１ａを成形加工するパイプ状部材の成形方法を図１１（ａ）〜（ｃ）に沿って説明する。
【００３１】
鋼製のパイプ素材ｍがプレス機１０ａに供給され、第１、第２可動型４４、４５が開放位置ｑ１よりプレス位置ｑ２に切換えられる。次いで、上型４６が退却位置ｑ７よりプレス位置ｑ８に切換えられ、パイプ素材ｍがパイプ載置面４３に沿って屈曲され、湾曲部ａ１を形成する曲げ加工が成される。
【００３２】
次いで、図１１（ｂ）に示すように上型４６上の直状型５３が退却位置ｑ７よりプレス位置ｑ８に切換えられ、パイプ素材ｍに凹部ｑを形成し、く字状閉断面ｕが形成され、第１のプレス加工工程が行われる。
次いで、図１１（ｃ）に示すように、上型４６は上昇して退却位置ｑ５に戻る。その上で、一対の挟持型５０、５１を退却位置ｑ３よりプレス位置ｑ４に切換え、く字状閉断面ｕを成している部位の両屈曲端を互いに当接させる第２のプレス加工工程が成される。
この後、第１の工程を完了したパイプ素材ｍはプレス機１０ａの型開きの後、取出され、図４のハイドロフォーム加工機１１に移され、図１のパイプ素材ｍと同様にハイドロフォーム加工され第２の工程を完了し、次いで、縮径部ｂａの内突部１０１ａの外周側基部ｅａがその位置を溶接部ｗとして処理され第３の工程が完了し、パイプ状補強部材１ａとなる。
【００３３】
完成品となったパイプ状補強部材１ａは図８に示すように、フロントピラー２及びルーフサイドレール３に補強部材として使用される。この場合も図１のパイプ状補強部材１と同様の作用効果が得られ、特に、図９に示すように内突部１０１ａの外周側基部ｅａをルーフサイドレールエクステンションアッパー３４に直接溶接して一体化でき、この部位の剛性強化をより確実に図ることができる。更に、縮径部ｂａを比較的上側に偏移させることが容易となり、空域部３ｂ（縮径部ｂａは空域部３ｂの下方に図示しない補助部を有する）を十分に確保し、図示しないレール等の収納を容易化できる。
【００３４】
上述のところにおいて、図２、３のプレス機１０では第１の工程で、まず、パイプ素材ｍに湾曲部ａ１を曲げ加工により形成し、次いで、パイプ素材ｍにく字状閉断面ｕが形成される第１のプレス加工工程が行われ、次いで、く字状閉断面ｕの両屈曲端を互いに当接させる第２のプレス加工工程が成されていた。図１０（ａ），（ｂ）のプレス機１０ａでは第１の工程で、パイプ素材ｍに湾曲部ａ１を曲げ加工するとほぼ同時にパイプ素材ｍにく字状閉断面ｕが形成され、次いで、く字状閉断面ｕの両屈曲端を互いに当接させる第２のプレス加工工程が成されていた。これに対し、第１のプレス加工工程と第２のプレス加工工程が成された後にパイプ素材ｍに湾曲部ａ１を曲げ加工により形成し第１の工程を完了させても良く、この場合も、曲げ加工を先に行う場合と同様の作用効果が得られる。
【００３５】
上述のところにおいて、図１、図８の各パイプ状補強部材１、１ａはその略中央に湾曲部ａ１を形成していたが複数箇所に湾曲部ａ１を形成しても良い。更に、図１、図８の各パイプ状補強部材１、１ａはその略後ろ半部側全域に縮径部ｂ、ｂａを形成していた。しかし、場合により、図１２（ａ）に示すように、パイプ状補強部材１ｂの長手方向の中間部に縮径部ｂｂを形成しても良く、図１２（ｂ）に示すように、パイプ状補強部材１ｃの長手方向の複数箇所に縮径部ｂｃ，ｂｄを形成しても良く、本発明のパイプ状部材の成形方法は長手方向の任意の個所に上述の縮径部を成形でき、これらの場合も、図１、図８の各パイプ状補強部材１、１ａと同様の作用効果が得られる。
【００３６】
上述のところにおいて、パイプ状補強部材１は鋼管として説明したが、場合により、その他のパイプ状素材を用いても良く、この場合も図１のパイプ状補強部材１と同様の作用効果が得られる。
【００３７】
【発明の効果】
以上のように、本発明によるパイプ状部材は、内突部が形成された縮径部とこれに連続する拡径部とを単一パイプ素材によりハイドロフォーム加工して形成するので、部品点数削減、組み付け工数低減を図れ、特に、前記内突部の外周側基部が溶接されるので、変形時に外周側基部が分離変形せず、同部の変形時の剛性を強化できる。
【００３８】
本発明によるパイプ状部材の成形方法は、第１の工程で内突部を形成し、第２の工程で内突部の形成された部位である縮径部とこれに連続する拡径部とを単一パイプ素材によりハイドロフォーム加工して形成し、第３の工程において内突部の外周側基部が溶接されるので、断面の外径変化（拡管率）の大きいパイプ状部材を単一パイプ素材により作業性良く成形でき、内突部による剛性の向上及びハイドロフォーム加工による加工硬化での剛性の向上を図ることができ、変形時に外周側基部が分離変形せず、変形時の剛性を強化したパイプ状部材を容易に作成できる。
【００３９】
特に、前記第１の工程は、第１のプレス加工工程と第２のプレス加工工程とを有するとした場合、パイプ素材を２度のプレス加工でく字状閉断面の両屈曲端を互いに当接変形させて縮径部に予備成形し、その上で第２の工程でハイドロフォーム加工により縮径部を含む全体を拡径成形することができ、作業性よく縮径部を含むパイプ状部材を成形できる。
【図面の簡単な説明】
【図１】本発明の一実施形態としてのパイプ状補強部材を示し、（ａ）は側面図、（ｂ）は要部切欠平面図である。
【図２】図１のパイプ状補強部材を成形するプレス機の平面図である。
【図３】図１のパイプ状補強部材を成形するプレス機の側面図である。
【図４】図１のパイプ状補強部材を成形するハイドロフォーム加工機の要部概略平面図である。
【図５】図１のパイプ状補強部材を成形するプレス機の加工工程の説明図で、（ａ）は曲げ加工の状態、（ｂ）は第１のプレス加工工程の状態、（ｃ）は第２のプレス加工工程の状態を示す。
【図６】図１のパイプ状補強部材を成形するプレス機の加工工程の説明図で、（ａ）は第２の工程完了状態、（ｂ）は第３の工程完了状態を示す。
【図７】図１のパイプ状補強部材の車両のルーフサイドレールに取付けた状態を示し、（ａ）は前部開口上端縁対向部での断面図であり、（ｂ）は後部開口上端縁対向部での断面図である。
【図８】本発明の他の実施形態としてのパイプ状補強部材の側面図である。
【図９】図９のパイプ状補強部材の縮径部をルーフサイドレールの後部開口上端縁対向部に取付けた状態の断面図である。
【図１０】図８のパイプ状補強部材を成形するプレス機を示し、（ａ）は要部平面断面図、（ｂ）は要部側面断面図である。
【図１１】図８のパイプ状補強部材を成形するプレス機の加工工程の説明図で、（ａ）は曲げ加工の状態、（ｂ）は第１のプレス加工工程の状態、（ｃ）は第２のプレス加工工程の状態を示す。
【図１２】本発明の適用された他のパイプ状補強部材を示し、（ａ）は第１の変形例を（ｂ）は第２の変形例を示す。
【図１３】従来のパイプ状部材の要部を示し、（ａ）は第１の例を（ｂ）は第２の例を示す。
【符号の説明】
１〜１ｃパイプ状補強部材（パイプ状部材）
１０１内突部
２フロントピラ
３ルーフサイドレール
５スライドドア（後ドア）
７後開口
ａ前側部（拡径部）
ｂ〜ｂｄ縮径部
ｍパイプ素材
ｑ凹部
ｕく字状閉断面
ｗ溶接部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pipe-shaped member molded into a predetermined shape by a single pipe material and a molding method thereof, and more particularly to a pipe-shaped member whose cross-sectional outer diameter changes at each position in the longitudinal direction and a molding method thereof.
[0002]
[Prior art]
Pipe-shaped members are used as components of various industrial equipment. In manufacturing such a pipe-shaped member, a pipe material having an outer diameter is appropriately adopted, which is deformed into a predetermined shape and completed as a pipe-shaped member, and then incorporated into each industrial device as a component. When processing such a pipe material as a product, a number of deformation processing methods are employed. For example, when a pipe-shaped member whose cross-sectional outer diameter changes at each position in the longitudinal direction is made of metal, it is known to perform diameter expansion molding by a hydroforming method.
According to this hydroform processing method, as shown in FIG. 13 (a), the pipe material can be formed as a pipe-shaped member 100 whose tube expansion rate changes at both ends in the longitudinal direction. The maximum value of the tube expansion rate, which is the cross-sectional shape change rate obtained by the above, is 5 to 10%.
[0003]
Therefore, in order to manufacture a pipe-shaped member with the tube expansion ratio changed at both ends in the longitudinal direction beyond that, as shown in FIG. 13 (b), two pipe materials 110 and 120 having different cross-sectional shapes are subjected to sheet metal processing. For example, a pipe 130 is manufactured by using a bracket 130 separately manufactured by the above method, or an appropriate molding process is performed using a pipe made of a completely different material other than metal.
[0004]
[Problems to be solved by the invention]
However, as shown in FIG. 13 (b), when a manufacturing method in which a plurality of pipe members 110, 120 are connected by a bracket 130, an increase in the number of parts, an increase in the number of welding operations, etc., and a stable strength are achieved. May not be obtained. On the other hand, the pipe-shaped member produced by the hydroforming method can reduce the number of parts, reduce the number of welding operations, and provide a stable strength, but cannot obtain a sufficient tube expansion rate as described above, and is restricted in shape. There is a problem.
Thus, if the pipe-shaped member obtained by the hydroforming method can be molded as if the cross-sectional area at each position in the longitudinal direction is sufficiently changed, it can be effectively used, and improvement is desired.
[0005]
For example, in a vehicle body structure in which the rear door is a slide door, the cross-sectional area of the closed cross section greatly changes because the accommodation space for the slide door rail is secured in the roof side rail. In such a vehicle body structure, when a single pipe-like member is continuously inserted inside the closed cross section of the front pillar and the roof side as a reinforcement of the roof side rail continuous from the front pillar, the pipe-like member is long. It is desired not to reduce the cross-sectional rigidity and the collision strength while having a cross-sectional shape corresponding to each cross-section of the side roof rail and the pillar at each position in the direction.
An object of the present invention is to provide a pipe-shaped member in which the area of a cross section at each position in the longitudinal direction is sufficiently changed, and a method for forming the same, based on the above problems.
[0006]
[Means for Solving the Problems]
  The pipe-shaped member according to the first aspect of the present invention has a reduced diameter portion in which an inner protrusion protruding inward in cross section is formed by press working and an enlarged diameter portion formed continuously from the reduced diameter portion., The outer peripheral side base of the inner protrusion is welded,The reduced diameter portion and the enlarged diameter portion are hydroformed.
  In this way, the diameter-reduced part where the inner protrusion is formed and the diameter-enlarged part continuing to this are formed by hydroforming with a single pipe material, so the number of parts and assembly man-hours can be reduced,In particular, since the outer peripheral base of the inner protrusion is welded, the outer peripheral base does not separate and deform during deformation, and the rigidity during deformation of the same can be enhanced..
[0008]
  Claim2The method for forming a pipe-shaped member according to the present invention includes a first step of forming an inner protrusion projecting inward in a cross-section by press working on a pipe material, and expanding the diameter of the pipe material by hydroforming, to form a pipe-shaped member A second step of moldingAnd a third step of welding the outer peripheral base of the inner protrusion.And the first step includes a first press working step of forming the pipe material in a square closed cross section, and both bent ends of the square closed cross section after completion of the first press working step. And a second press working step in which the two are compressed and brought into contact with each other in a direction approaching each other.
  In this way, the inner protrusion is formed in the first step,In the second stepFormed by hydroforming with a single pipe material a reduced diameter part that is a part where the inner protrusion is formed and an enlarged diameter part that continues to this,Since the outer peripheral side base of the inner protrusion is welded in the third step,Pipe-shaped members with a large outer diameter change rate (expansion rate) can be molded with a single pipe material with good workability, and the rigidity by the inner protrusion and the work hardening by hydroforming can be improved. CanA pipe-shaped member with enhanced rigidity at the time of deformation can be easily created without causing the outer peripheral base to separate and deform during deformation.. In particular, the pipe material is preliminarily formed into a reduced diameter part by deforming both bent ends of the closed section with a double press process, and then hydroformed in the second step. Can be formed into a pipe-shaped member including a reduced diameter portion with good workability.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a pipe-shaped member and a method for forming the pipe-shaped member as an embodiment of the present invention will be described.
A pipe-shaped reinforcing member 1 as a pipe-shaped member shown in FIGS. 1 (a) and 1 (b) is continuously formed on the front pillar 2 and the rear end of the front and rear openings 6 and 7 on the side of the vehicle body (not shown). It is fitted over the roof side rail 3 to enhance the rigidity of these parts. The pipe-shaped reinforcing member 1 includes a front side portion a that is a diameter-enlarged portion having a relatively large-diameter curved portion a1, and a reduced-diameter portion b in which a portion facing the upper edge opposing portion of the rear opening 7 is reduced in diameter. It is formed continuously.
[0012]
Here, as shown in FIG. 1A, the front side portion a which is a diameter-enlarged portion of the pipe-shaped reinforcing member 1 is opposed to the front end side of the front pillar 2 and the roof side rail 3, and the front pillar 2 of the same portion and The roof side rail 3 is welded to the inner member side at a plurality of locations in the longitudinal direction. 7A shows a welded portion w to the roof side rail inner 32 on the front end side of the roof side rail 3, and FIG. 7B shows a reduced diameter portion b on the rear side of the roof side rail 3. The welding part w to the roof side rail extension upper 34 in is shown.
[0013]
The pipe-shaped reinforcing member 1 used in this way employs a single steel pipe as the pipe material m, and has a curved portion a1 by a press machine 10 and a hydroform machine 11 as shown in FIGS. The processed front side portion a and reduced diameter portion b are processed.
As shown in FIGS. 2 and 3, the press machine 10 used here has a base 12 and a vertical base frame 13 extending above the base 12 and forms a pipe mounting surface 14 on the base 12. The fixed mold 15, the first and second movable molds 16, 17 are arranged on both sides, and the upper mold 18 is attached to the vertical base frame 13.
[0014]
The fixed mold 15 on the base 12 is equipped with a stopper 20 and a first pressurizer 19 for switching the stopper 20 between the retreat position p1 and the stopper position p2. The first movable die 16 forms a reduced diameter portion b, and a second pressurizing machine 21 that switches to a retreat position p3, a restraining position p4, a pressurizing position p5, and a pre-pressurizing position p5 'is attached. The second movable die 17 forms a curved portion a1 in the pipe material m, and a third pressurizer 22 that switches between the retreat position p6 and the pressurization position p7 is attached. The upper die 18 forms a concave portion q (see FIG. 5B) in the reduced diameter portion b, and a fourth pressurizing machine 23 for switching between the retreat position p8 and the press position p9 is mounted. The upper mold 18 is supported by a plurality of horizontal base frames 24, and these horizontal base frames 24 are supported by a rectangular vertical base frame 13. In FIG. 3, reference numeral 25 denotes a detent member that extends upward from both ends of the upper mold 18 and is slidably fitted to the side of the horizontal base frame 24.
[0015]
As shown in FIG. 4, the hydroforming machine 11 includes a mold clamping machine (not shown) having upper and lower molds 111 and 112 and high-pressure water supply adapters 26 and 26 arranged on both sides thereof. In the upper and lower molds 111 and 112, fitting grooves (see FIG. 6 (a)) 113 and 114 for closely fitting the pipe material m after the first step, which will be described later, are formed in the upper and lower joint surfaces thereof. Each high-pressure water supply adapter 26 is formed so as to be fitted to both ends (see FIGS. 1 and 4) of the pipe material m. The high-pressure water supply adapter 26 has a structure that can be closely fitted to both ends n of the pipe material, and communicates the super high-pressure water supply system of the main body (not shown) of the hydroforming machine 11 with the pipe material m. Supported by the base 27. The adapter support 27 is equipped with a pressure mechanism (not shown) inside, thereby applying a pressure PW that presses both the high-pressure water supply adapter 26 and the pipe material m in the axial direction, thereby expanding the diameter of the pipe material m. Promote processing.
[0016]
A pipe-shaped member forming method for forming the pipe-shaped reinforcing member 1 of FIG. 1 using such a press machine 10 and hydroforming machine 11 will be described with reference to FIGS. (C), FIG. 6 (a), It demonstrates along (b).
Prior to forming the pipe-shaped member 1, a steel pipe material m having a predetermined outer diameter and a predetermined length is supplied to the press machine 10. In this case, the pipe material m has an outer diameter that is a predetermined amount smaller than the outer diameter of the front side portion a of the pipe-shaped reinforcing member 1. In this case, the pipe material m is selected such that the outer diameter of the front side portion a of the pipe-shaped reinforcing member 1 is obtained when the pipe material m is deformed at a tube expansion rate of 5 to 10%.
[0017]
The press machine 10 holds the stopper 20 at the retracted position p1, the first and second movable molds 16 and 17 at the retracted positions p3 and p6, and the upper mold 18 at the retracted position p8. The pipe material m is supplied to the pipe placement surface 14. Next, as shown in FIGS. 2 and 5A, the first and second movable molds 16 and 17 are switched from the retreat positions p3 and p6 to the restraining position p4 and the pressurizing position p7, and the pipe material m is bent to the bending portion a1. Form. Next, as shown in FIG. 5B, only the first movable mold 16 moves from the restraining position p4 to the pre-pressurization position p5 ′, and the upper opening h between the fixed mold 15 and the movable molds 16 and 17 is enlarged. . Then, the upper die 18 descends from the retreat position p8 and reaches the press position p9, and a first press working step for forming the recess q in the pipe material m is performed. As a result, a rectangular closed cross section u is formed at the portion facing the upper mold 18 of the pipe material m.
[0018]
Next, as shown in FIG. 5 (c), the upper mold 18 rises again and returns to the retreat position p8. Then, the stopper 20 protrudes from the retreat position p1 to the stopper position p2, and suppresses the upward shift of the portion where the concave portion q of the pipe material m is formed. In this state, only the first movable mold 16 moves from the pre-pressing position p5 ′ and reaches the pressing position p5, and the press surfaces of the fixed mold 15 and the first movable mold 16 form a rectangular closed section u. A second press working step is performed in which the two bent ends of the portions being pressed are compressed toward each other and brought into contact with each other. Thus, the first step can be completed by the first and second press working steps, and this portion can be formed as the reduced diameter portion b. In this case, an inner protrusion 101 having an inner protrusion protruding inward in the closed cross section is formed in the reduced diameter part b of the pipe material m.
[0019]
Next, the pipe material m that has completed the first step is taken out after the mold opening of the press machine 10 and taken out and fitted into the fitting groove 114 of the lower mold 112 as shown in FIG. 4 and the hydroforming machine 11. Then, the mold is closed by a mold clamping machine (not shown) and is closely fitted in the upper and lower fitting grooves (see FIG. 6A) 113 and 114.
Next, when the high pressure water supply adapters 26 are respectively attached to both ends n of the pipe material m while being sandwiched between the upper and lower molds 111 and 112, high pressure water is supplied from the main body (not shown) of the hydroforming machine 11 to the inside of the pipe material m. , The pipe material m is diameter-expanded and formed into the pipe-shaped reinforcing member 1, and the second step is completed. At this time, the inner protruding portion 101 on the inner protruding portion of the reduced diameter portion b receives the hydraulic pressure of the ultra-high pressure water and the internal gap is crushed, and the inner protrusion 101 is close to a plate shape as shown in FIG. The protrusion 101 is formed.
[0020]
In this way, the pipe material m is preliminarily formed into the reduced diameter portion b by deforming both bent ends of the rectangular closed section u close to each other by pressing twice, and then hydroforming in the second step. The entire diameter including the reduced diameter portion b can be expanded and the reinforcing member 1 including the reduced diameter portion b can be formed with good workability.
Next, the hydroforming machine 11 is opened, the high-pressure water supply adapter 26 is removed, and the pipe-shaped reinforcing member 1 is taken out.
Further, the pipe-shaped reinforcing member 1 is cut at the end n on the reduced diameter portion b side among the ends n connected to the high-pressure water supply adapters 26 at both ends. Further, as shown in FIG. 6 (b), the pipe-shaped reinforcing member 1 has the outer base portion e of the inner protrusion 101 of the reduced diameter portion b treated as the welded portion w, completing the third step. And finished product.
[0021]
Thus, since the outer peripheral side base e of the inner protrusion 101 becomes the welded portion w in the third step, the outer peripheral base e is not separated and deformed at the time of deformation, and the rigidity at the time of deformation can be enhanced.
The finished pipe-shaped reinforcing member 1 is used as a reinforcing member for the front pillar 2 and the roof side rail 3 of the vehicle V as shown in FIG.
As shown in FIGS. 1 (a), 1 (b) and 7, the pipe-shaped reinforcing member 1 formed in this way has an inner protrusion 101 disposed laterally at its reduced diameter portion b, and at its outer end. A certain outer peripheral side base e is located on the side end side of the vehicle. As shown in FIG. 7, rounded piece-like portions are formed on the upper and lower sides of the outer peripheral side base e, respectively, and the pipe-like reinforcing member 1 has a transverse heart-shaped cross-sectional shape as a whole and is reduced in diameter.
[0022]
The diameter-reduced portion b of the pipe-shaped reinforcing member 1 having such a shape is formed with a sufficiently large tube expansion rate by forming the inner protrusion 101. That is, when the pipe-shaped reinforcing member 1 is formed by changing the cross-sectional area at each position in the longitudinal direction by hydroforming, the pipe expansion rate is about 5 to 10% in normal hydroforming. However, here, a pipe material m having a relatively large outer shape is prepared in advance, a part of the pipe material is reduced in diameter, and then the diameter is increased. Here, in the diameter reduction processing, the inner protrusion 101 is recessed in the diameter reduction portion b by press processing, and diameter reduction molding is performed, so that a sufficiently large tube expansion rate can be secured. Next, the entire pipe material m was clamped with a press 10, and hydroforming was performed with a normal pipe expansion rate of about 5 to 10%, thereby forming the pipe-shaped reinforcing member 1. For this reason, the pipe-shaped reinforcing member 1 is processed in the same manner as when the pipe expansion rate is formed with a sufficiently large tube expansion rate. Moreover, since the reduced diameter portion b is welded to the outer peripheral side base e which is the outer end of the inner protrusion 101, the bending strength can be improved by suppressing the deformation of the outer peripheral base e during bending deformation.
[0023]
A use example in which such a pipe-shaped reinforcing member 1 is fitted over the front pillar 2 at the top of the front and rear openings 6 and 7 on the side of the vehicle body (not shown) and the roof side rail 3 continuous with the rear end will be described below.
As shown in FIG. 7 (a), the roof side rail 3 is a closed structure in which the roof side rail outer 31 and the roof side rail inner 32 are overlapped with each other and the inner and outer flanges are welded at the upper opening of the front opening 6 of the vehicle. It is formed as a cross section. The front side portion a of the pipe-shaped reinforcing member 1 is fitted into the closed cross-section portion, is brought into contact with the roof side rail inner 32, and is welded to each other by a plurality of welding portions w. In addition, although the same structure is taken also in the upper part part of the front pillar 2 continuing to the front side with respect to the welding part of the front side part a of the pipe-shaped reinforcement member 1 and the roof side rail inner 32, duplication description is abbreviate | omitted.
[0024]
As shown in FIG. 7B, the roof side rail 3 is formed of a main portion 3a, an airspace portion 3b, and an auxiliary portion (not shown) below the upper portion of the rear opening 7 of the vehicle. The main portion 3a is formed to have a relatively small closed cross-sectional structure in which the roof side outer panel 33 and the roof side rail extension upper 34 are integrally coupled. Here, the reduced diameter portion b of the pipe-shaped reinforcing member 1 is fitted and inserted into the closed cross-section space, and the contact portions between the reduced diameter portion b and the roof side rail extension upper 34 are welded along the longitudinal direction. It is welded intermittently.
[0025]
A slide door rail for a slide door (not shown) is attached to the roof inner panel 35 extending to the deepest part of the air space portion 3b.
When a vehicle V in which such a pipe-shaped reinforcing member 1 is fitted into the front pillar 2 and the roof side rail 3 is subjected to a frontal collision or an offset collision during traveling, an overload is applied from the front pillar 2 toward the roof side rail 3. Here, the front end portions of the front pillar 2 and the roof side rail 3 are sufficiently reinforced by the relatively large-diameter front portion of the pipe-shaped reinforcing member 1, so that bending can be sufficiently suppressed.
[0026]
In particular, as shown in FIGS. 1 (b) and 7 (b), the pipe-shaped reinforcing member 1 has a heart-shaped cross-sectional shape at a portion continuing from the stepped portion D to the reduced-diameter portion b, and an outer peripheral side at the outer end. The inner protrusion 101 where the base e is located is arranged in a horizontal direction. For this reason, the outer peripheral side base portion e particularly strengthens the rigidity and the collision strength of the reduced diameter portion b, so that it becomes the rigidity center of the reduced diameter portion b (a position where the compressive force and the tensile force in the cross-sectional direction are balanced and canceled). The deviation δ of the shaft center y1 (see the shaft center line L1), which is the center of rigidity of the front side portion a, is relatively small with respect to the shaft center y2 (see the shaft center line L2). In addition, the rigidity of the outer peripheral side base e is increased by welding the outer peripheral side base e. From this point, even if the step portion D of the roof side rail 3 starts to bend, the inner protrusion 101 of the pipe-shaped reinforcing member 1 can sufficiently suppress the bending displacement.
[0027]
As described above, the pipe-shaped reinforcing member 1 as a single component can be easily inserted into the front pillar 2 and the roof side rail 3 in which the closed cross-sectional shape at each position in the longitudinal direction greatly changes and is integrally coupled. This can sufficiently strengthen the rigidity of the same part. In particular, the pipe-shaped reinforcing member 1 can be continuously inserted over the roof side rail 3 from the front pillar 2, thereby contributing to the reduction in the number of parts, the number of welding steps, and the cost. Furthermore, the rigidity of the reduced diameter portion b can be improved by the inner protrusion 101, and the rigidity of the entire pipe-shaped reinforcing member 1 can be improved by work hardening by hydroforming.
[0028]
In the above-mentioned place, the pipe-shaped reinforcing member 1 has the inner protrusion 101 disposed at the reduced diameter portion b, and the inner protrusion 101 is disposed in the lateral direction with the outer peripheral base portion e positioned at the outer end. However, it may be configured as shown in FIGS. Here, the pipe-shaped reinforcing member 1a is formed in the same manner as the pipe-shaped reinforcing member 1 of FIG. 1 except that the inner protrusion 101a is arranged in the vertical direction, and is used in the same manner. The same reference numerals are assigned to the same members, and duplicate descriptions are omitted.
In this case, the pipe-shaped reinforcing member 1a has the outer base ea of the inner protrusion 101a in the reduced diameter part ba arranged on the lower side, the inner protrusion 101a extends upward from the lower outer base ea, and is contracted. It arrange | positions vertically in the closed cross section of the diameter part ba.
[0029]
As the pipe-shaped reinforcing member 1a used in this way, a press machine 10a as shown in FIGS. 10A and 10B and a hydroforming machine 11 similar to the above are used.
The press machine 10a used here has a base 40 and a vertical base frame 41 extending upward, and an auxiliary base 42 is integrally attached to a part of the base 40, and a pipe mounting surface 43 is attached. The first movable mold 44 and the second movable mold 44 are disposed on both sides of the upper mold 46 and the upper mold 46 supported on the vertical base frame 41 side is disposed above the pipe placement surface 43.
First and second pressurizers 47a and 47b are mounted on the base 40, whereby the first and second movable dies 44 and 45 are switched between the open position q1 and the press position q2. Third and fourth pressurizers 48 and 49 are mounted on the first and second movable dies 44 and 45, whereby the pair of clamping dies 50 and 51 are moved into the retreat position q3 and the press position q4 (FIG. 11 (c)). Switch to).
[0030]
The upper mold 46 is slidably supported on the vertical base frame 41 side so as not to rotate, and is switched between the retreat position q5 and the plus position q6 by the fifth pressurizer 50 supported on the vertical base frame 41 side. A straight die 53 is slidably supported on the upper die 46 and its support member 461, and the straight die 53 is switched between a retreat position q7 and a press position q8 by a sixth pressurizer 52.
A pipe-shaped member forming method for forming the pipe-shaped reinforcing member 1a of FIG. 8 using such a press machine 10a and hydroform processing machine 11 will be described with reference to FIGS. 11 (a) to 11 (c).
[0031]
The steel pipe material m is supplied to the press machine 10a, and the first and second movable dies 44 and 45 are switched from the open position q1 to the press position q2. Next, the upper die 46 is switched from the retreat position q7 to the press position q8, the pipe material m is bent along the pipe placement surface 43, and bending is performed to form the curved portion a1.
[0032]
Next, as shown in FIG. 11 (b), the straight die 53 on the upper die 46 is switched from the retreat position q7 to the press position q8 to form a recess q in the pipe material m, and a square closed section u is formed. Then, the first pressing process is performed.
Next, as shown in FIG. 11 (c), the upper mold 46 moves up and returns to the retreat position q5. Then, a second pressing process is performed in which the pair of sandwiching dies 50 and 51 are switched from the retreat position q3 to the press position q4, and both bent ends of the portion forming the square closed cross section u are brought into contact with each other. Made.
After that, the pipe material m that has completed the first step is taken out after the mold opening of the press machine 10a, and is taken out and transferred to the hydroforming machine 11 in FIG. 4, and hydroforming is performed in the same manner as the pipe material m in FIG. Then, the second step is completed, and then, the outer peripheral side base ea of the inner protrusion 101a of the reduced diameter portion ba is processed with the position as the welded portion w, and the third step is completed, whereby the pipe-shaped reinforcing member 1a is obtained. .
[0033]
The completed pipe-shaped reinforcing member 1a is used as a reinforcing member for the front pillar 2 and the roof side rail 3, as shown in FIG. Also in this case, the same effect as that of the pipe-shaped reinforcing member 1 of FIG. 1 can be obtained. In particular, as shown in FIG. The rigidity of this part can be strengthened more reliably. Furthermore, it becomes easy to shift the reduced diameter portion ba relatively upward, and the air space portion 3b (the reduced diameter portion ba has an auxiliary portion (not shown) below the air space portion 3b) is sufficiently secured, and the rail (not shown) Etc. can be easily stored.
[0034]
2 and 3, in the first step, the bending portion a1 is first formed in the pipe material m by bending, and then the closed cross section u is formed in the pipe material m. The first press working step is performed, and then the second press working step is performed in which both bent ends of the rectangular closed section u are brought into contact with each other. In the press machine 10a shown in FIGS. 10 (a) and 10 (b), in the first step, when the bending portion a1 is bent on the pipe material m, a substantially square closed cross section u is formed on the pipe material m. A second press working step in which both bent ends of the letter-shaped closed section u are brought into contact with each other has been performed. On the other hand, after the first press process and the second press process, the curved portion a1 may be formed in the pipe material m by bending to complete the first process. The same effect as when bending is performed first can be obtained.
[0035]
In the above description, each of the pipe-shaped reinforcing members 1 and 1a in FIGS. 1 and 8 has the curved portion a1 formed at the approximate center thereof, but the curved portion a1 may be formed at a plurality of locations. Further, each of the pipe-shaped reinforcing members 1 and 1a shown in FIGS. 1 and 8 is formed with reduced diameter portions b and ba in the entire region around the rear half. However, depending on the case, as shown in FIG. 12 (a), a reduced diameter portion bb may be formed in the intermediate portion in the longitudinal direction of the pipe-shaped reinforcing member 1b. As shown in FIG. The reduced diameter portions bc and bd may be formed at a plurality of locations in the longitudinal direction of the reinforcing member 1c, and the pipe-shaped member molding method of the present invention can form the above-mentioned reduced diameter portions at arbitrary locations in the longitudinal direction. In this case, the same effect as the pipe-shaped reinforcing members 1 and 1a shown in FIGS. 1 and 8 can be obtained.
[0036]
In the above description, the pipe-shaped reinforcing member 1 has been described as a steel pipe. However, in some cases, other pipe-shaped materials may be used, and in this case, the same function and effect as the pipe-shaped reinforcing member 1 of FIG. 1 can be obtained. .
[0037]
【The invention's effect】
  As described above, the pipe-shaped member according to the present invention is formed by hydroforming the reduced diameter portion in which the inner protrusion is formed and the enlarged diameter portion continuous with the single pipe material, thereby reducing the number of parts. , Reduce assembly man-hours,In particular, since the outer peripheral base of the inner protrusion is welded, the outer peripheral base does not separate and deform during deformation, and the rigidity during deformation of the same can be enhanced..
[0038]
  The method for forming a pipe-shaped member according to the present invention forms an inner protrusion in the first step,In the second stepFormed by hydroforming with a single pipe material a reduced diameter part that is a part where the inner protrusion is formed and an enlarged diameter part that continues to this,Since the outer peripheral base of the inner protrusion is welded in the third step,A pipe-shaped member with a large change in outer diameter (pipe expansion rate) of the cross section can be molded with a single pipe material with good workability, and the rigidity can be improved by the inner protrusion and the work hardening by hydroforming. ,The outer peripheral base is not separated and deformed at the time of deformation, and a pipe-shaped member with enhanced rigidity at the time of deformation can be easily produced.
[0039]
  In particular, when the first process includes a first press process and a second press process, the pipe material is subjected to two press processes so that both bent ends of the rectangular closed cross section are brought into contact with each other. The pipe-shaped member can be deformed in contact and preformed into a reduced diameter portion, and then the entire diameter including the reduced diameter portion can be formed by hydroforming in the second step, and the reduced diameter portion can be formed with good workability. Can be moldedThe
[Brief description of the drawings]
1A and 1B show a pipe-shaped reinforcing member according to an embodiment of the present invention, in which FIG. 1A is a side view, and FIG.
FIG. 2 is a plan view of a press machine for forming the pipe-shaped reinforcing member of FIG.
3 is a side view of a press machine for forming the pipe-shaped reinforcing member of FIG. 1. FIG.
4 is a schematic plan view of a main part of a hydroforming machine for forming the pipe-shaped reinforcing member of FIG. 1. FIG.
FIGS. 5A and 5B are explanatory diagrams of a processing step of a press machine for forming the pipe-shaped reinforcing member of FIG. 1, wherein FIG. 5A is a bending state, FIG. 5B is a first pressing step, and FIG. The state of a 2nd press work process is shown.
6A and 6B are explanatory views of a processing step of the press machine for forming the pipe-shaped reinforcing member of FIG. 1, in which FIG. 6A shows a second step completion state and FIG. 6B shows a third step completion state.
7 shows a state where the pipe-shaped reinforcing member of FIG. 1 is attached to the roof side rail of the vehicle, (a) is a cross-sectional view of the front opening upper edge opposite portion, (b) is the rear opening upper edge. It is sectional drawing in an opposing part.
FIG. 8 is a side view of a pipe-shaped reinforcing member as another embodiment of the present invention.
9 is a cross-sectional view of a state in which a reduced diameter portion of the pipe-shaped reinforcing member in FIG. 9 is attached to a rear opening upper edge opposite portion of a roof side rail.
10A and 10B show a press machine for forming the pipe-shaped reinforcing member of FIG. 8, wherein FIG. 10A is a plan sectional view of the main part, and FIG. 10B is a side sectional view of the main part.
FIGS. 11A and 11B are explanatory views of a processing step of the press machine for forming the pipe-shaped reinforcing member of FIG. 8, wherein FIG. 11A is a bending state, FIG. 11B is a first pressing step, and FIG. The state of a 2nd press work process is shown.
FIG. 12 shows another pipe-shaped reinforcing member to which the present invention is applied, in which (a) shows a first modification and (b) shows a second modification.
FIG. 13 shows a main part of a conventional pipe-shaped member, in which (a) shows a first example and (b) shows a second example.
[Explanation of symbols]
1-1c Pipe-shaped reinforcing member (pipe-shaped member)
101 Inner protrusion
2 Front Pillar
3 Roof side rail
5 Sliding door (rear door)
7 Rear opening
a Front side (expanded part)
b ~ bd reduced diameter part
m Pipe material
q Recess
u-shaped closed section
w Welded part

Claims

A diameter-reduced portion formed with an inner protrusion protruding inward in cross section by press working, and a diameter-expanded portion formed continuously from the reduced-diameter portion, and the outer peripheral side base of the inner protrusion is welded A pipe-shaped member , wherein the reduced diameter part and the enlarged diameter part are hydroformed.

A first step of forming an inner protrusion projecting inwardly in the cross section of the pipe material by pressing, a second step of forming a pipe-shaped member by expanding the diameter of the pipe material by hydroforming , A third step of welding the outer peripheral side base portion of the protrusion , wherein the first step includes a first press working step of forming the pipe material in a square-shaped closed cross section, and the first press. A pipe-shaped member forming method comprising: a second pressing step of compressing and abutting both bent ends of the rectangular closed cross section in a direction approaching each other after the processing step is completed.